|Title of Invention||
ENDODONTIC INSTRUMENT FOR ROOT CANAL STERILIZATION
|Abstract||The present invention relates to an instrument for sterilizing root canal(s) during endodontic procedures. The instrument comprises of an elongate member closely fitting the root canal and a handle, which remains in the pulp chamber. The antimicrobial medicament placed in the pulp chamber is transported throughout the root canal by the capillary action exerted by the capillary space between the root canal wall and the closely fitting elongate member: This capillary action is enhanced by presence of capillarity enhancing devices such as vertical or spiral capillary groove or shallow wells on the elongate member. The instrument is made of non-toxic metal, alloys or disposable plastics. The instrument when made of silver has additional antimicrobial properties due to the release of Silver (Ag+) ions. It is provided in a set of several instruments of varying sizes, lengths and embodiments so as to meet the varied requirements of endodontic procedures.|
3. DESC RIPTION
Field of invention
The present invention relates in general to the field (»f Dentistry and partieularly to the field of endodontics, that is, the art and practice of root canal treatment. More particularly, the present invention relates to an instrument for sterilizing the dental root canal during endondontic procedures.
The Prior State of the Art
Endodontics deals with infections and diseases of dental pulp and the periapical tissues. Dental pulp is found in the pulp chamher and root canals of the tooth. Disease causing microorganisms gain access to the pulp either through dental caries, tooth fracture, trauma to the tooth or periodontal disease. The infected pulp has to be removed either by extracting the tooth or by performing an endodontic procedure, such as a root canal treatment. In this procedure an opening is made in the crown of the tooth to access the pulp chamber and root canal, which is then cleaned and shaped with endodontic tools that removes the contaminated pulp and widens the root canal. The root canal is irrigated during the procedure to flush out the pulp tissue and antimicrobial medicaments are used to kill the microorganisms inside of the root canal. This procedure may be repeated in two to three sittings spaced over several days till the root canal is sterili/ed and there are no signs and symptoms of infection. Finally the root canal is filled with an inert material coated with a sealer cement to prevent future contamination of the root canal.
The methods currently in use for sterilization of the root canals is by irrigating with antimicrobial fluids like sodium hypochlorite and placement of antimicrobial medicaments like formocresol or gluteraldehyde in the pulp chamber, fhe irrigation (»f the root canal, and replacement of the medicament are carried out over two or more sittings. After this, if no clinical symptom is detected and no abnormal clinical condition is observed inside the root canal, the final filling of root canal is carried out. Other methods have been described where bactericidal ultraviolet rays and more potent sterilizing fluids or those with improved characteristics have been used.
The problems with the current methods for sterilization of the root canals are many and varied. The rool canal is a small space with an inside diameter of about I to 1.5 mm, wider at the coronal part of the root and considerably narrow at the apical part of the root. Thus it is not possible to carry the medicament into this small space using the existing apparatus. The pressure exerted f>y the air column in this small space prevents thorough exposure of the entire surface of the root canal to the medicaments. Also presently there is no method by which the bactericidal medicaments can be transported and kept in place along the entire surface of the root canal, for a period of time, so that proper sterilization takes place. This leads to an extension in the number of sittings for the treatment, till the desired sterilization takes place. In the upper teeth, gravity prevents the flow of the medicament into the root canals leading to improper
sterili/ation. Other apparatus available are either eumhersome to use or are so expensive that it has not been put into common practice.
There is currently a need in the art for a simple and cITcctive instrument for sterilizing root canals during endodontic procedures.
()bjecti>es of the Invention
It is an outstanding object of the present invention to provide an instrument, which transports and keeps in place antimicrobial medicaments along the entire length of the root canal, for a specified period of time, thus sterilizing the root canal.
It is a further object of the present invention to provide an instrument that can be placed in all kinds of root canal(s) including narrow or tortuous canal(s), in such a w ay that it can be sealed inside the root canal(s) for a period of time and later easilv retrieved.
It is an additional object of the present invention to provide an instrument that is an economical, simple and efficient apparatus for the sterilization of root canals.
Summary of invention
Ihe present invention is an instrument for sterilizing the root canals during endodontic treatment. In order to attain the objects of the invention the present invention basically consists of an elongate member, which can easily negotiate the root canal(s) and a handle by which it can be placed or withdrawn from the root canal. J he length of the said instrument is such that it can be placed inside the root canal and the tooth sealed from the outside environment. One embodiment of the instrument has a smooth surface, another has shallow wells and still another embodiment has vertical or spiral capillary grooves, all such devices for the purpose of carrying or transporting antimicrobial medicaments along the entire length of the root canal. The basic principle underlying the invention is the capillary action provided by the small space between the instrument and the root canal wall, which is enhanced by the presence of vertical or spiral capillary grooves and shallow wells. These capillarity-enhancing devices may be present separately in different emb(»diments of the invention or it may be incorporated into a single embodiment of the inventi(»n. The instrument is provided in a set of different types, sizes and shapes, both autoclavable and disposable, so as to meet all requirements in root canal sterilization.
B> wa> of example, the material employed in the tools of (he present invention may include any non-toxic materials like gold, platinum, palladium, and tungsten. One preferred embodiment is the instrument made from silver, which has intrinsic antimicrobial properties. Other embodiments further include alloys like stainless steel or nickel - titanium and disposable plastics.
These and other objeets and features of the present invention will beeome fully apparent from the following deseription and appended elaims, or may be learned by the praetiee of the invention as set forth hereinafter.
Brief deseription of the Drawinf^s
An extensive deseription of the present invention will be rendered with referenee to the speeifie embodiments that arc illustrated in the appended drawings. As these drawings depict only exemplary embodiments, they should not be construed as imposing any limitation on the present invention's scope. As such, the present invention will be described and explained with additional specificity and detail through use of the accompanying drawings in which:
FKi. 1 is a top view showing
KKil. 3 is a top view showing another embodiment of a root canal sterilizing instrument according to the present invention;
1 Kil. 4 is a top view of yet another embodiment of a root canal sterilizing instrument according to the present invention;
FKi. 5 is a view of a cross section of a tooth, which has undergone a root canal procedure and has received the tool of FKi. 4 within the root canal. The access opening of the teeth has been closed with a temporary filling after keeping a cotton pellet, saturated with an antimicrobial solution, in c(»ntact with the tool;
FKi. 6 is an exploded cross sectional view of the instrument of FKi. 1 in the root canal, illustrating the working of the instrument.
DFTAILKI) DESCRIPTION OFTIIF PKKFFKUFI) KMIJODIMFNTS
FKiS. 1-4 illustrates the various embodiments of a root canal sterilizing instrument. Each of these emb With reference now to FKi. I, the root canal sterilizing instrument has an elongate member 10, a vertical capillary groove II along its entire length and a handle 12. The elongate member II) is shaped in such a way that it can negotiate the root canals easily and its width is such that it lies in close proximity to the root canal surface. A vertical capillary groove(s) II is present on the said tool
from the base of the handle 12, starting from the proximal end of the elongate member 10 and extending to its tip. Aeeordin^ to the si/e of the tool and ease of manufaeture, the vertieal eapillary of sueh a shape so as not to allow the entire instrument to slip into the root eanal and also to make plaeement and removal of the tool from the root eanal easy. The length of the entire instrument is sueh that when plaeed in the r
With referenee now to FKi. 3, this embodiment of the root eanal sterilizing instrument has an elongate member 30, numerous medieament earrying shallow wells 31 along its entire length and a handle 32. The elongate member 3() is shaped in sueh a way that it ean negotiate the n»ot eanals easily and its width is sueh that it lies in elose proximity to the root eanal surfaee. The medieament earrying shallow wells 31 is present on the said tool from the base of the handle 32, starting from the proximal end of the elongate member 30 and extending to its tip. I he number and depth of these medieament-earrying wells 31 along the elongate member 30 ean be inereased or deereased, as long as it does not affect the strength and rigidity of the tool. The handle 32 is preferably integral to the tool, although it is a\ailable as a nonintegral attaehment. The said handle 32 is generally of sueh a shape so as not to all. 1 he length of the entire instrument is sueh that when plaeed in the root eanal, the handle remains in the pulp ehamber and thus the teeth can be easily sealed from the outside environment. A set of instruments with differing lengths is provided so as to meet all requirements of the proeedure.
With referenee now to KK;. 4, this embodiment of the root canal sterilizing instrument has an elongate member 40 and a handle 42. (he elongate member 40
is sliaped in such a way that it can ncj^otiatc the root canals easily and its width is such that it lies in close proximity to the root canal surface. The surface of the elongate member 4(1 is generally smooth. The handle 42 is preferably integral to the tool, although it is available as a nonintegral attachment. 1 he said handle 42 is generally of such a shape so as not to allow the entire instrument to slip into the root canal and also to make placement and removal of the tool from the root canal easy. The length of the entire instrument is such that when placed in the root canal, the handle remains in the pulp chamber and thus the teeth can be easily sealed from the outside environment. A set of instruments with differing lengths is provided so as to meet all requirements The tool is made of a "metallic materiaT' which is understood, in the context of the present invention, to mean a metal, a material that includes a metal, or a combination of metals. Examples of materials, which can be employed for the manufaclure of the (ool include stainless steel, gold, platinum, palladium, silver, tungsten, nickel - titanium, and the like. It can also be made of any material, which is non-toxic, flexible and are capable of being formed into tools, which permit insertion into root canals, like, for example, plastics. Ihe cost of the said instrument is reduced if the elongate member is made hollow, but this will lead to a reduction in strength (»f the instrument.
Since the tool will likely encounter blood, saliva, water, end(»dontic pulp material and other fluid and cellular material, and should be sterile when used, the material employed is also preferably autocla>able, corrosion resistant, and oxidation resistant. However, disposable embodiments, preferably made of plastics, are also available.
The preferred material used to form the root canal sterilizing instrument is Silver. This is because Silver releases antimicrobial Siher (Ag+) Ions in an aqueous medium, similar to what is found in the root canal, especially when batheil in antimicrobial ntedicaments. Siher ions react with the proteins of microorganisms and inhibit cellular metabolism thereb) acting as a disinfectant. A tool made of Silver is rigid enough to be extended into a root canal, yet ductile or pliant enough to negotiate root canal areas. It also has physical properties conduci\e to being formed into tools that permit insertion into the root canal. Silver is also autoclavable and is easily replaced if corrosion or oxidation sets in. riius Silver can also be used in a disposable embodiment of the present invention.
One embodiment of a material used in the present invention is a tool made of stainless steel or nickel titanium alloys. The advantage with this material is that a radiograph can be taken with the tool in the root canal to get the correct working length of the root. Radiographic length determination can be done with the tool made of any material, which is radiopaque with a mass X-ray absorption coefficient of 1.49 or below, so that the instrument shows clearly in the radiograph.
I he elongate member (eg. Ut, 20, M), 40) is preferably sul)stantially straight, and flexible enough to negotiate the angles of the root canal. However, it will be appreciated that the elongate member may be angled an> where along its length
so that it is convenient to manipulate. Optionally, the handle is designed for convenient manipulation of the sterilizing instrument, such as In hein^ an The root canal stcrili/in instruments is provided in a set comprising of anj one embodiment as shown in FKiS. 1-4, or a mix of all or several of these. It has in the set, instruments of >arying sizes and lengths so as to meet all the situations, which arises due to the various sizes and lengths of the root canal(s). The set of instruments may also contain tools made of different materials, for example, a set with tools made of Silver, plastics and stainless steel or nickel titanium all(»ys.
The tool, according to the present invention, has generally the same diameter as files or other tools typically used in endodontic procedures, for example, or other sizes, which fit into a root canal and allow negotiation therein. The tools may he tapered such as in the shape of a standard ISO tapered file, for example. The length of the tool is such that it can he placed in the tooth and the tooth sealed from the outside environment. J he length of the elongate member is determined according to the measured average lengths of the root canal(s), which are for example, 5mm, Smm, 10mm and 13mm in the molars and premolars, and 17nim and 20 mm for the incisors and canines. Ihe length and width of the handle is preferably constant at 3mm X 2inm, for example, so that it remains in the pulp chamber and the tooth can be sealed from outside en\ ironment.
FKi. 5 illustrates an example of the root canal sterilizati(m instrument depicted in flii. 4 (shaded for clarity) placed within a root canal 51 of a prepared to ri(i. 6 shows an exploded view of the root canal sterilizing instrument of FKi. I placed within a root canal 60. ihe \ertical groo> c II of the instrument transports the sterilizing medicaments 61 from the pulp chamber through capillar) action. The capillary space between the r(»ot canal wall and the instrument 10, leads t(» the capillary action, thus allowing the antimicrobial medicament 61 to bathe the entire area of the root canal, pnulucing effective sterilizati
iiicdicaincnt bathing it sterili/es the root canal surl'acc. Ihesc devices may be present in(li> idually or one or more mav be present on the same embodiment of the tool, depending on the ease of manufacture.
Accordin«> to one method of use, an initial radiographic ima^e of a tooth is made and the root canal(s) length is estimated. Then the pulp chamber of the tooth is opened, the pulp is removed and biomechanical preparation done. The root canal(s) are then dried with paper points. A suitable embodiment of the root canal sterilizing instrument according to the present irucntion is setected, its length depending on the estimated root len(>th and the si/e dependin on the last endodontic file used for biomechanical preparation, usually called the master apical file. The selected tool is then coated with the antimicrobial medicament and placed in the r
4. I claim: -
1. An ciulodontic instrument for stcrili/in the root canal, the tool comprisin 2. An endodontic tool for sterilizing the root canal as recited in claim 1, wherein the elon fits the root canal and its tip lies at or > cry near the apex; and
wherein the length of the ehuigate member is usijall\ the measured averaj»e lengtli of root eanal(s), whieh is Smm, 8mm, 10mm and 13mm in the mohirs and premohirs, and 17mm and 2(J mm for the ineisors and eanines.
3. An endodontie tool for sterilizing the root eanal as reeited in elaim I, wherein the instrument works using the prineiple of eapillar> aetion exerted by the eapillarv spaee between the closely fitting elongate member and the walls of the ro(»t eanal.
4. An endodontie tool for sterilizing the root eanal as recited in elaim 1, wherein the elongate member has capillarity enhancing devices on it such as a shallow \ertical or spiral capillary groove or shallow medicament carrying wells, extending from the proximal end to the tip of the instrument; and
wherein the said capillarit> enhancing devices ma> be present on the elongate member in any number or any width according to the ease i»f manufacture.
5. An endodontic tool for sterilizing the root canal as recited in claim 1, wherein
the handle is configured in such a way that it d(»es not slip into the ro(»t eanal and
remains in the pulp chamber; and
whcrin the said handle is of such a shape and size that there is enough space left in the pulp chamber so that a cotton pellet saturated with an antimicrobial medicament can be placed and the tooth can be sealed from the outside environment with a temporary filling; and
wlierin the said handle can be used to remove the tool from the tooth after a peri(»d of time such that proper sterilization of the root canal occurs; and
wherein the said handle may be an integral or a nonintcgral attachment to the cl(»ngate member; and
wherein the handle niav have a hole in the center through which a thread mav be passed to secure the handle.
6. An endodontic tool for sterilizing the root canal comprising of an elongate member and a handle, wherein the tool is made from an> material, which is nontoxic, has sufficient rigidity and ductility for insertion even into narrow and lsi\ c, and non-oxidizing and the elongate member can he sfdid or hollon.
7. An endodontic to(»l for sterilizing the r(»ot canal as recited in claim 6, wherein the tool is made of any metal including gold, platinum, palladium, tungsten and the like.
S. An endodontic tool tor sterilizing the root canal as recited in claim 6, w herein the tool is made of silver, such that the sterilizing effect of the tool is enhanced due to the release of Silver (Ag+) ions into the root canal in presence of antimicrobial medicaments; and
nluM'ciii llie instrument made of silver is in ii disposahle r 9. An endiKlontie UHA lor sterili/inf* the ro(»t eanal as reeitetl in elaim 6, wherein
tlie tool is made of any alloy ineludin stainless steel, niekel titanium and the like.
10. An endodontie tool for sterilizing the root eanal as reeited in elaim 6, wherein
11. An endodontie tool for sterilizing the r(»ot eanal eomprisin^ of an elongate
inemher and a handle, wherein the tool is made of a material with mass X-ray
eoeffieient of 1.49 or less; and
wherein, the eorreet root eanal len 12. A method for sterilizin a root eanal, eomprisin^;
(i) plaein (ii) plaein^ a eotton pellet soaked in antimierohial medieament in the pulp ehamher in elose proximity to the handle of tool; and
(iii) elosin (i\) retrievinj» the tool from the tooth, the fully sterilized root eanal ean be then filled.
13. An endodontie tool for sterilizing the root eanal eomprisin^ of an ehm^ate
member and a handle, wherein the tool is provided in a set of varying lengths,
shapes and embodiments so that all requirements of endodontie sterilization ean
|Indian Patent Application Number||236/CHE/2004|
|PG Journal Number||05/2007|
|Date of Filing||17-Mar-2004|
|Name of Patentee||SHRI. VIJAYAN RAVIKUMAR|
|Applicant Address||ALAKAPURI, PATTITHARA POST, TRITHALA, PALAKKAD, KERALA 679534|
|PCT International Classification Number||A61C 3/02|
|PCT International Application Number||N/A|
|PCT International Filing date|